14 C-glutamate and 14 C-arginine were spreaded on leaves of six-day old barley ( Hordeum vulgare L.) seedlings that were treated with NaCl 200 mmol/L. The result showed that the pathway of arginine→ornithine→proline existed in the six-day old barley seedlings and was provoked remarkably by NaCl treatment. After seven days, proline accumulation contributed via the arginine→ornithine→proline pathway was 1.0-1.5 folds of that via the glutamate→proline pathway. The activation of arginine→ornithine→proline pathway by salt stress in the salt-tolerant cultivar “Jian 4" was 1.7-2.0 folds of that in the salt-sensitive cultivar “KP 7", which suggested that the activation of arginine→ornithine→proline pathway in barley seedlings played an important role in improving salt tolerance of plants.
盐胁迫激活大麦幼苗脯氨酸合成的鸟氨酸途径
赵福庚 孙诚 刘友良*
（南京农业大学农学系，农业部作物生长调控重点开放实验室，南京210095）
摘要: 200 mmol/L NaCl处理结合14C-Glu和14C-Arg叶面饲喂6 d龄大麦(Hordeum vulgare L.)幼苗，结果证明6 d龄大麦幼苗体内普遍存在Arg(谷氨酸)→Orn(鸟氨酸)→Pro(脯氨酸)途径。盐胁迫明显激活了Arg→Orn→Pro途径，胁迫处理7 d，大麦幼苗叶片和根系中该途径对Pro含量上升的贡献是Glu→Pro途径的1.0～1.5倍。耐盐的“鉴4” 品种Arg→Orn→Pro途径对Pro含量上升的贡献是对盐敏感的“科品7号” 的1.7～2.0倍，结果表明盐胁迫下Arg→Orn→Pro途径的激活对大麦幼苗耐盐性的提高具有重要意义。
关键词： 脯氨酸；鸟氨酸途径；盐胁迫；大麦幼苗
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